Metal-containing indoaniline compound and optical recording medium employing the compound

ABSTRACT

A metal-containing indoaniline compound having the formula: ##STR1## wherein M is a metal atom of Group VIII, Ib, IIb, IIIb, IVa, Va, VIa or VIIa of the Periodic Table or its halide or oxide, rings A, B, C, D, E and F may have substituents, each of K 1  K 2  and K 3  is a residue of a substituted or unsubstituted aromatic amine, each of l, m and n is 0 or 1, provided l+m+n=2 or 3, and p is 2, 3 or 4.

The present invention relates to a novel metal-containing indoanilinecompound and an optical recording medium employing the compound.

In recent years, the optical recording utilizing laser has beendeveloped particularly for the storage of high density informationrecording and reproduction of the recorded information.

An optical disc may be mentioned as a typical example of such opticalrecording medium.

In general, the optical disc is designed for high density informationrecording which is effected by irradiation of a laser beam collimated tohave a diameter of about 1 μm onto a thin recording layer formed on asubstrate of a disc shape. The information recording is effected by athermal deformation of the recording layer, such as the decomposition,evaporation or dissolution, which takes place upon absorption of thelaser beam energy at the irradiated portions of the recording layer. Onthe other hand, the reproduction of the recorded information is done byreading a difference in the reflectance between the portion thermallydeformed by the laser beam and the portion where no such deformation hasoccurred.

Accordingly, the optical recording medium is required to have highabsorptivity for a laser beam of a particular wavelength used for therecording since it is required to absorb the energy of the laser beamefficiently, and also to have a high reflectance to the laser beam of aparticular wavelength for use in the reproduction so as to carry out theaccurate reproduction of the recorded information.

Various constructions have been proposed for the optical recordingmedium of this type.

For example, Japanese Unexamined Patent Publication No. 97033/1980discloses a medium having a single layer of a phthalocyanine dye formedon a substrate. However, the phthalocyanine dye is poor in thesensitivity and has a difficulty such that its decomposition temperatureis high and its vapor deposition is difficult. Besides, its solibilityin an organic solvent is extremely poor, and it is hardly possible toapply it by coating.

Japanese Unexamined Patent Publiucation No. 83344/1983 discloses arecording medium having a recording layer composed of a phenalene dye,and Japanese Unexamined Patent Publication No. 224793/1983 discloses arecording medium having a recording layer composed of a naphthoquinonedye. However, such a dye has a drawback that the reflectivity is lowwhile it has an advantage that it can readily be vapor-deposited. If thereflectivity is low, the contrast in the reflectance between thenon-recorded portion and the recorded portion irradiated with the laserbeam tends to be low, and the reproduction of the recorded informationtends to be difficult. Further, in general, an organic dye has adrawback that it is inferior in the storage stability.

With respect to these problems, Japanese Patent Application No.59777/1987 proposes a medium having a metal-containing indoanilinecompound incorporated in the recording layer as a medium having improvedreflectance (contrast) and solubility to an organic solvent. However,such a medium has some problems as a recording medium required to have awell balanced properties with respect to both the initialcharacteristics (the dependency of sensitivity on the thickness of therecording layer, the secondary distorsion) and the storage stability(the coating layer, the pigment powder).

It is an object of the present invention to provide a novelmetal-containing indoaniline compound having PF₆ ⁻ as a counter anionwhich provides well balanced properties with respect to both the initialcharacteristics and the storage stability as a recording medium and toprovide an optical recording medium employing such a compound.

The present invention provides a metal-containing indoaniline compoundhaving the formula: ##STR2## wherein M is a metal atom of Group VIII,Ib, IIb, IIIb, IVa, Va, VIa or VIIa of the Periodic Table or its halideor oxide, rings A, B, C, D, E and F may have substituents, each of K¹,K² and K³ is a residue of a susbtituted or unsubstituted aromatic amine,each of 1, m and n is 0 or 1, provided l+m+n=2 or 3, and p is 2, 3 or 4.

The present invention provides also an optical recording mediumcomprising a substrate and a recording layer containing a dye formed onthe substrate wherein the recording is effected by irradiation of alaser beam to impart a thermal deformation of the recording layer andthe reproduction is done by reading difference in the relectance betweenthe deformed portion and the undeformed portion, wherein said dye is ametal-containing indoaniline compound of the formula I.

In the accompanying drawings:

FIG. 1 shows the visible range absorption spectrum of themetal-containing indoaniline compound of the present invention havingPF₆ ⁻ as a counter anion, as presented in Example 1. In this Figure, theordinate represents the absorbance and the abscissa represents thewavelength (nm).

FIG. 2 shows the absorption spectrum and reflection spectrum of a thincoating layer of the metal-containing indoaniline compound of example 1.The ordinate at the left represents the absorbance and the ordinate atthe right represents the relectance. The abscissa represents thewavelength (nm).

Now, the structure of the metal-containing indoaniline compound of theformula I will be described in detail.

In the formula I, the residue of a substituted or unsubstituted aromaticamine for K¹, K² and K³ may be, for example, a residue of a heterocyclicamine containing a nitrogen atom, an oxygen: atom or a sulfur atom suchas a tetrahydroquinoline or a julolidine, or a group represented by theformula: ##STR3## wherein each of X^(a) and Y^(b) is a hydrogen atom, analkyl group, an acylamino group, an alkoxycarbonylamino group, analkylsulfonylamino group, an alkoxy group or a halogen atom, and each ofR^(a) and R^(b) is a hydrogen atom or a C₁₋₂₀ alkyl group, an arylgroup, an alkenyl group or a cycloalkyl group, which may be substituted,or R^(a) and R^(b) may together form a ring via an oxygen atom, anitrogen atom or a sulfur atom.

The substituents for the alkyl group, the aryl group, the alkenyl groupor the cycloalkyl group for R_(a) and R_(b) may be, for example, analkoxy group, an alkoxyalkoxy group, an alkoxyalkoxyalkoxy group, anallyoxy group, an aryl group, an aryloxy group, a cyano group, a nitrogroup, a hyroxyl group, a tetrahydrofuryl group, an alkylsulfonylaminogroup, an acyloxy group and a halogen atom. Further, as the substituentsfor the aryl group and the cycloalkyl group, an alkyl group or a vinylgroup may be mentioned.

Among the compounds represented by the formula I, preferred are thoserepresented by the formula: ##STR4## wherein M is a metal atom of GroupVIII, Ib, IIb, IIIb, IVa, VA, VIa or VIIa of the Periodic Table, each ofR⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², X¹, X², X³, Y¹, Y² and Y³ is a hydrogen atom,a halogen atom, an alkyl group, an alkoxy group, an acylamino group, analkoxycarbonylamino group or an alkylsulfonylamino group, each of R¹,R², R³, R⁴, R⁵ and R⁶ is a hydrogen atom, a C₁₋₂₀ alkyl group, an arylgroup, an alkenyl group or a cycloalkyl group, which may be substituted,each of 1, m and n is 0 or 1, provided l+m+n=2 or 3, and p is 2, 3 or 4.

Particularly preferred are those represented by the formula: ##STR5##wherein M is a metal atom of Ni, Cu, Co, Zn or Pe, each of X⁴, X⁵ and X⁶is a hydrogen atom or a C₁₋₄ alkyl group, each of R¹³, R¹⁴, R¹⁵, R¹⁶,R¹⁷ and R¹⁸ is a C₁₋₈ alkyl group, an alkoxyalkyl group, analkoxyalkoxyalkyl group, an alkoxyalkoxyalkoxyalkyl group, anallyloxyalkyl group, an arylalkyl group, an aryloxyalkyl group, acyanoalkyl group, a hydroxyalkyl group, a tetrahydrofurylalkyl group, analkylsulfonylaminoalkyl group, an acyloxyalkyl group or an alkenylgroup, each of R¹⁹, R²⁰ and R²¹ is a hydrogen atom, a C₁₋₄ alkyl groupor a halogen atom, and each of 1, m and n is 0 or 1, provided l+m+n=2 or3.

Among them, especially preferred are those of the formula III whereineach of R¹³, R¹⁴, R¹⁵ and R¹⁶ is a C₁ -6 alkyl group, each of R¹⁹, R²⁰and R²¹ is a hydrogen atom or a C₁₋₄ alkyl group, and each of X⁴, X⁵ andX⁶ is a C₁₋₄ alkyl group.

The novel metal-containing indoaniline compound of the formula I has anabsorption in the wavelength range of from 600 to 900 nm, and amolecular absorption coefficient of as high as at least 10⁵ cm⁻¹, andthus it has excellent characteristics suitable for an optical recordingmedium.

The metal-containing indoaniline compound of the formula I used in thepresent invention may be prepared, for example, by subjecting a compoundof the formula: ##STR6## wherein R⁷ and R⁸ are as defined above, tooxidative condensation with a hydrochloride of a compound of theformula: ##STR7## wherein X¹, Y¹, R¹ and R² are as defined above, toobtain a compound of the formula: ##STR8## wherein R¹, R², R⁷, R⁸, X¹and R¹ are as defined above, and then reacting the above compound with acompound of the formula: ##STR9## wherein R³, R⁴, R⁹, R¹⁰, X² and Y² areas defined above, and/or a compound of the formula: ##STR10## whereinR⁵, R⁶, R¹¹, R¹², X³ and Y³ are as defined above, and a compound of theformula:

    M.sup.2+ (Cl.sup.31 ).sub.2 ##STR11## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9, R.sup.10, R.sup.11, R.sup.12, X.sup.1, X.sup.2, X.sup.3, Y.sup.1, Y.sup.2, Y.sup.3 and M are asdefined above, or a compound of the formula: ##STR12## wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.7, R.sup.8, R.sup.9, R.sup.10, X.sup.1, X.sup.2, Y.sup.1, Y.sub.2 and M are as defined above, and then reacting the above compound with a compound of the formula NH.sub.4 PF.sub.6 (counter ion exchanger).

When the metal-containing indoaniline compound obtained by the aboveprocess is to be used for an optical recording medium of the presentinvention, the dye may be a single compound or a mixture of compoundshaving different substituents or different coordination numbers.

The optical recording medium of the present invention comprisesessentially a substrate and a recording layer containing themetal-containing indoaniline compound. However, if necessary, anunderlayer may be formed on the substrate, or a protective layer may beformed on the recording layer.

The substrate in the present invention may be transparent or opaque tothe laser beam to be used. The substrate may be made of a materialcommonly used for a support for recording materials, such as glass,plastic, paper or a metal in a sheet or foil form. However, the plasticis most suitable from various viewpoints. The plastic includes anacrylic resin, a methacrylate resin, a vinyl acetate resin, a vinylchloride resin, nitrocellulose, a polyethylene resin, a polypropyleneresin, a polycarbonate resin, a polyimide resin, an epoxy resin and apolysulfone resin. Among them, an injection molded polycarbonate resinsubstrate is particularly preferred from the viewpoints of highproductivity, costs and moisture resistance.

In the optical recording medium of the present invention, the recordinglayer containing the metal-containing indoaniline compound has athickness of from 100 Å to 5 μm, preferably from 1,000 Å to 3 μm. Thelayer may be formed by employing a thin layer-forming method commonlyemployed, such as a vacuum vapor deposition method, a sputtering method,a doctor blade method, a casting method, a spinner method or a dippingmethod. If necessary, a binder may be employed. As such a binder, aconventional binder such as PVA, PVP, nitrocellulose, cellulose acetate,polyvinyl butyral or polycarbonate may be used. The weight ratio of themetal-containing indoaniline compound to the resin is preferably atleast 1%. When the layer is formed by a spinner method, the rotationalspeed is preferably from 500 to 5,000 rpm. In some cases, after the spincoating, heat treatment or treatment with a solvent vapor may beapplied.

Further, for the purpose of improving the stability or light-resistanceof the recording medium, the recording layer may contain a transitionmetal chelate compound (such as acetyl acetonate chelate, bisphenyldithiol, salicylaldehyde oxime or bisdithio-α-diketone) as a Singletoxygen quencher.

Further, an additional dye may be incorporated. The additional dye maybe a different compound of the same type or a dye of different type suchas a triaryl methane dye, an azo dyestuff, a cyanine dye or squaleriumdye.

When the recording layer is formed by a doctor blade method, a castingmethod, a spinner method or a dipping method, particularly by a coatingmethod such as a spinner method, a solvent having a boiling point offrom 120 to 160° C. such as tetrachloroethane, bromoform, dibromoethane,ethyl cellosolve, xylene, chlorobenzene or cyclohexanone is suitablyemployed as the solvent for coating.

Among them, a cellosolve solvent such as methyl cellosolve or ethylcellosolve, or a ketone alcohol solvent such as diacetone alcohol or3-hydroxy-3-methyl-2-butanone is particularly preferred since it cansuitably be used without impairing the injection molded polycarbonateresin substrate which is preferred as the substrate.

The recording layer of the optical recording medium of the presentinvention may be provided on each side of the substrate, or on one sideonly.

Recording of information onto the recording medium thus obtained, iseffected by irradiating a laser beam, preferably a semiconductor laserbeam, collimated to have a diameter of about 1 μm onto the recordinglayer formed on each side or one sioe of the substrate. A thermaldeformation such as the decomposition, evaporation or fusion due to theabsorption of the laser energy takes place at the portions of therecording layer irradiated by the laser beam.

Reproduction of the recorded information is done by reading a differencein the reflectance between the portion where the thermal deformationoccurred by the laser beam and the portion where no such thermaldeformation took place.

The laser beam useful for the optical recording medium of the presentinvention includes a N₂ laser, a He-Cd laser, an Ar laser, a He-Nelaser, a rubby laser, a semiconductor laser and a color laser. Asemiconductor laser is particularly preferred from the viewpoint of thelight weight, easiness in handling and compact structure.

The metal-containing indoaniline compound having PF₆ ⁻ as a counteranion of the present invention is excellent not only in the initialcharacteristics but also in the storage stability, whereby bothproperties are well balanced. Accordingly, an optical recording mediumusing such a compound is very useful.

Now, the present invention will be described in further detail withreference to Examples. However, it should be understood that the presentinvention is by no means restricted by such specific Examples.

The secondary distortion of the initial characteristics of the opticalrecording medium was calculated by the following equation.

Seconadry distortion (dB) =secondary harmonic carrier level - primaryharmonic carrier level

EXAMPLE 1

(a) Preparation

1.07 g of a compound of the formula: ##STR13## was dissolved in 500 mlof ethanol, and a solution of 0.44 g of NiCl₂.6H₂ O in 250 ml of waterwas added thereto. The mixture was stirred at room temperature for onehour. Then, a solution of 1.26 g of NH₄ PF₆ in 250 ml of water wasdropwise added thereto. Formed precipitates were collected by filtrationunder suction, washed with water and then dried to obtain 1.45 g(theoretical yield: 90%) of a metal-containing indoaniline compound ofthe formula: ##STR14##

The visible range absorption spectrum (in Chloroform) of this compoundwas λ_(max) 800 nm (ε_(max) 160000) as shown in FIG 1. The data obtainedby TG-DSC show a heat generation initiating temperature of 186° C.,whereby the heat generation peak was not sharp.

(b) Recording medium

0.15 g of the metal-containing indoaniline compound obtained inPreparation (a) was dissolved in 10 g of 3-hydroxy-3-methyl-2-butanone,and the solution was filtered through a filter of 0.22 μm to obtain asolution. 5 ml of this solution was dropped on an injection moldedpolycarbonate resin substrate (5 inches) with grooves having a depth of700 Å and a width of 0.7 μm and coated by a spinner method at arotational speed of 1,000 rpm. After coating, the coating layer wasdried at 60° C. for 10 minutes. The coating layer had a maximumabsorption wavelength of 810 nm and a reflectance of 42% (830 nm). Theshape of the spectrum was broad.

FIG. 2 shows the absorbance and reflection spectrum of the coatinglayer.

(c) Optical recording

While rotating the above recording medium at a speed of 4 m/sec, asemiconductor laser beam having a central wavelength of 830 nm wasirradiated with a pulse width of 500 nsec, whereby the C/N ratio was 55dB at an output of 6 mW. The sensitivity was flat without depending onthe thickness of the layer, and the initial characteristics wereexcellent with a secondary distortion of -40 dB. Yet, the storagestability (at 65° C. under a relative humidity of 80%) was excellent.Thus, it was excellent as an optical recording medium.

COMPARATIVE EXAMPLES 1-1 and 1-2

Metal-containing indoaniline compounds of the following formulas (X) and(XI) were respectively coated in the same manner as in Example 1 toprepare discs. Then, the initial characteristics (the dependency ofsensitivity on the thickness of the recording layer, and the secondarydistortion) and the storage stability (the change in the reflectance ofthe coating layer, and the change in the absorbancy of the dye powder)were evaluated and compared. As shown in Table 1, each of the discsprepared from these compounds was inferior in both properties to theoptical recording medium of Example 1 of the present invention and wasunsuitable as an optical recording medium with the properties being outof balance. ##STR15##

EXAMPLE 2

(a) Preparation

0.54 g of a compound of the formula: ##STR16## and 0.56 g of a compoundof the formula: ##STR17## were dissolved in 500 ml of ethanol, and asolution of 0.44 g of NiCl₂.6H₂ O in 100 ml of water was added thereto.The mixture was stirred at room temperature for one hour.

Then, a solution of 1.26 g of NH₄ PF₆ in 100 ml of water was dropwiseadded thereto. Formed precipitates were collected by filtration undersuction, washed with water and dried to obtain 1.44 g of a mixture ofthe metal-containing indoaniline compounds of the following formulas:##STR18##

The visible region absorption spectrum (in chloroform) of this productwas λ_(max) 800 nm (ε_(max) 159000).

(b) Recording medium

0.15 g of the mixture of the metal-containing indoaniline compoundsobtained in Preparation (a) was dissolved in 10 g of diacetone alcoholand filtered through a coil filter of 0.22 μm to obtain a solution. 5 mlof this solution was dropped on an injection molded polycarbonate resinsubstrate (5 inches) with grooves having a depth of 700 Å and a width of0.7 μm and coated by a spinner method at a rotational speed of 700 rpm.After coating, the coating layer was dried at 60° C. for 10 minutes.

The maximum absorption wavelength of the coating layer was 810 nm, andthe reflectance was 44% (830 nm). The shape of the spectrum was broaderthan that of a single compound.

(c) Optical recording

While rotating the above recording medium at a speed of 4 m/sec, asemiconductor laser beam with a central wavelength of 830 nm wasirradiated with a pulse width of 500 nsec, whereby the C/N ratio was 54dB at an output of 6 mW. The sensitivity was flat without depending onthe thickness of the recording layer, and the initial characteristicswere excellent with a secondary distortion of -42 dB. Yet, the storagestability (at 65° C. under a relative humidity of 80%) was excellent.Thus, the recording medium was excellent as an optical recording medium.These results are shown in Table 1.

COMPARATIVE EXAMPLES 2-1 and 2-2

The mixtures of metal-containing indoaniline compounds represented bythe following formulas XII and XIII were respectively coated in the samemanner as in Example 2 to prepare discs, and the initial characteristics(the dependency of sensitivity on the thickness of the recording layer,and the secondary distortion) and the storage stability (the change inthe reflectance of the coating layer, and the change in the absorbanceof the dye powder) were evaluated and compared. As shown in Table 1,each of the discs prepared from these mixtures was inferior in bothproperties to the optical recording medium of Example 2 of the presentinvention, and was unsuitable as an optical recording medium with theproperties being out of balance. ##STR19##

                                      TABLE 1                                     __________________________________________________________________________                                   Storage stability (65° C.,                                             80% RH, 500 hrs)                                           Initial characteristics                                                                          Change in the                                              Dependency of sensitivity                                                                        reflectance                                                                          Change in the                                       of the thickness of the                                                                    Secondary                                                                           of the coating                                                                       absorbance of                                  Formula                                                                            recording layer                                                                            distortion                                                                          layer  the dye powder                          __________________________________________________________________________    Example 1                                                                            (VIII)                                                                             Suitable (flat)                                                                            -40 dB                                                                              2.3%   1.1%                                    Comparative                                                                          (X)  Rather unsuitable                                                                          -30 dB                                                                              5.0%   4.2%                                    Example 1-1 (abrupt increase)                                                 Comparative                                                                          (XI) Suitable (flat)                                                                            -40 dB                                                                               25%    20%                                    Example 1-2                                                                   Example 2                                                                            (IX) Suitable (flat)                                                                            -42 dB                                                                              0.9%   0.8%                                    Comparative                                                                          (XII)                                                                              Rather unsuitable                                                                          -28 dB                                                                              4.4%   4.1%                                    Example 2-1 (abrupt increase)                                                 Comparative                                                                          (XIII)                                                                             Suitable (flat)                                                                            -40 dB                                                                               27%    23%                                    Example 2-2                                                                   __________________________________________________________________________

EXAMPLE 3

Instead of the dye employed in Example 1, each of the compoundsidentified in Table 2 was prepared and coated on a substrate in the samemanner as in Example 1 to obtain a substrate having a thin coating layerwith the maximum absorption wavelength as identified in Table 2. To thethin coating layer thus obtained, writing was conducted by means of asemiconductor laser as a light source, whereby pits of uniform and clearshapes were obtained. The sensitivity and the C/N ratio were excellent.The initial characteristics (the dependency of sensitivity on thethickness of the recording layer, and the secondary distortion) wereexcellent. Yet, the storage stability was excellent. Thus, it wasexcellent as an optical recording medium.

                                      TABLE 2                                     __________________________________________________________________________     ##STR20##                                                                                                       Maximum absorp-                                                               tion wavelength                                                               of the thin                                No.                                                                              M R.sup.x                                                                           R.sup.y                                                                           K                     coating layer                              __________________________________________________________________________    3-1                                                                              Ni                                                                              H   H                                                                                  ##STR21##            810                                        3-2                                                                              " "   "                                                                                  ##STR22##            809                                        3-3                                                                              Ni                                                                              H   H                                                                                  ##STR23##            812                                        3-4                                                                              " "   "                                                                                  ##STR24##            810                                        3-5                                                                              " "   "                                                                                  ##STR25##            812                                        3-6                                                                              " "   "                                                                                  ##STR26##            813                                        3-7                                                                              Ni                                                                              H   H                                                                                  ##STR27##            780                                        3-8                                                                              " "   "                                                                                  ##STR28##            782                                        3-9                                                                              " "   "                                                                                  ##STR29##            782                                        3-10                                                                             " "   "                                                                                  ##STR30##            783                                        3-11                                                                             Ni                                                                              2-CH.sub.3                                                                        H                                                                                  ##STR31##            815                                        3-12                                                                             " "   "                                                                                  ##STR32##            782                                        3-13                                                                             " 6- or 7-Cl                                                                        "                                                                                  ##STR33##            835                                        3-14                                                                             " H   "                                                                                  ##STR34##            808                                        3-15                                                                             Ni                                                                              H   H                                                                                  ##STR35##            808                                        3-16                                                                             " "   "                                                                                  ##STR36##            808                                        3-17                                                                             " 6-CH.sub.3                                                                        "                                                                                  ##STR37##            812                                        3-18                                                                             " H   "                                                                                  ##STR38##            812                                        3-19                                                                             Ni                                                                              H   H                                                                                  ##STR39##            812                                        3-20                                                                             Cu                                                                              "   "                                                                                  ##STR40##            808                                        3-21                                                                             Co                                                                              "   "                                                                                  ##STR41##            808                                        3-22                                                                             Ni                                                                              6- or 7-Cl                                                                        2-CH.sub.3                                                                         ##STR42##            840                                        3-23                                                                             Cu                                                                              H   H                                                                                  ##STR43##            804                                        3-24                                                                             " "   "                                                                                  ##STR44##            784                                        3-25                                                                             Fe                                                                              "   "                                                                                  ##STR45##            802                                        3-26                                                                             " "   "                                                                                  ##STR46##            802                                        3-27                                                                             Co                                                                              H   H                                                                                  ##STR47##            788                                        3-28                                                                             " "   "                                                                                  ##STR48##            790                                        3-29                                                                             Cu                                                                              6- or 7-Cl                                                                        2-CH.sub.3                                                                         ##STR49##            835                                        3-30                                                                             Co                                                                              H   "                                                                                  ##STR50##            795                                        3-31                                                                             Ni                                                                              H   H                                                                                  ##STR51##            790                                        3-32                                                                             " "   "                                                                                  ##STR52##            790                                        3-33                                                                             " "   "                                                                                  ##STR53##            795                                        3-34                                                                             " "   "                                                                                  ##STR54##            776                                        3-35                                                                             Ni                                                                              H   H                                                                                  ##STR55##            760                                        3-36                                                                             " "   "                                                                                  ##STR56##            795                                        3-37                                                                             " "   "                                                                                  ##STR57##            794                                        3-38                                                                             " "   "                                                                                  ##STR58##            805                                        3-39                                                                             Ni                                                                              H   H                                                                                  ##STR59##            803                                        3-40                                                                             " "   "                                                                                  ##STR60##            797                                        3-41                                                                             " "   "                                                                                  ##STR61##            789                                        3-42                                                                             " "   "                                                                                  ##STR62##            795                                        3-43                                                                             Ni                                                                              H   H                                                                                  ##STR63##            788                                        3-44                                                                             " "   "                                                                                  ##STR64##            776                                        3-45                                                                             " "   "                                                                                  ##STR65##            786                                        3-46                                                                             " "   "                                                                                  ##STR66##            773                                        3-47                                                                             Ni                                                                              H   H                                                                                  ##STR67##            786                                        3-48                                                                             " "   "                                                                                  ##STR68##            774                                        3-49                                                                             " "   "                                                                                  ##STR69##            785                                        3-50                                                                             " "   "                                                                                  ##STR70##            786                                        3-51                                                                             Ni                                                                              H   H                                                                                  ##STR71##            815                                        3-52                                                                             " "   "                                                                                  ##STR72##            816                                        3-53                                                                             " "   "                                                                                  ##STR73##            802                                        3-54                                                                             " "   "                                                                                  ##STR74##            808                                        3-55                                                                             Ni                                                                              H   H                                                                                  ##STR75##            801                                        3-56                                                                             " "   "                                                                                  ##STR76##            798                                        3-57                                                                             " "   "                                                                                  ##STR77##            799                                        3-58                                                                             " "   "                                                                                  ##STR78##            814                                        3-59                                                                             Ni                                                                              H   H                                                                                  ##STR79##            805                                        3-60                                                                             " "   "                                                                                  ##STR80##            732                                        3-61                                                                             " "   "                                                                                  ##STR81##            829                                        3-62                                                                             " "   "                                                                                  ##STR82##            807                                        3-63                                                                             Ni                                                                              H   H                                                                                  ##STR83##            817                                        3-64                                                                             " "   "                                                                                  ##STR84##            816                                        3-65                                                                             " "   "                                                                                  ##STR85##            800                                        3-66                                                                             " "   "                                                                                  ##STR86##            800                                        3-67                                                                             Ni                                                                              H   H                                                                                  ##STR87##            788                                        3-68                                                                             " "   "                                                                                  ##STR88##            790                                        3-69                                                                             " 4-CH.sub.3                                                                        6-CH.sub.3                                                                         ##STR89##            812                                        3-70                                                                             " "   "                                                                                  ##STR90##            808                                        __________________________________________________________________________

Table 3 shows specific examples of the metal-containing indoanilinecompounds which can suitably be used for the optical recording medium ofthe present invention in addition to the compounds used in the precedingExamples.

                  TABLE 3                                                         ______________________________________                                         ##STR91##                                                                    M    R.sup.x R.sup.y     K                                                    ______________________________________                                        Ni   H       H                                                                                          ##STR92##                                           "    "       "                                                                                          ##STR93##                                           "    "       "                                                                                          ##STR94##                                           "    "       7-OCH.sub.3                                                                                ##STR95##                                           Ni   H       7-NHCOCH.sub.3                                                                             ##STR96##                                           "    "       6-NHCOCH.sub.3                                                                             ##STR97##                                           "    "       7-NHCOOC.sub.2 H.sub.5                                                                     ##STR98##                                           "    2-CH.sub.3                                                                            4-CH.sub.3                                                                                 ##STR99##                                           Pd   H       H                                                                                          ##STR100##                                          Zn   "       "                                                                                          ##STR101##                                          Ti   H       H                                                                                          ##STR102##                                          Fe   "       "                                                                                          ##STR103##                                          VO   "       "                                                                                          ##STR104##                                          Cr   "       "                                                                                          ##STR105##                                          Pt   "       "                                                                                          ##STR106##                                          Ni   "       "                                                                                          ##STR107##                                          Ni   H       H                                                                                          ##STR108##                                          "    "       7-CN                                                                                       ##STR109##                                          "    "       7-NO.sub.2                                                                                 ##STR110##                                          Mn   "       H                                                                                          ##STR111##                                          Ni   "       "                                                                                          ##STR112##                                          "    "       "                                                                                          ##STR113##                                          Ni   H       H                                                                                          ##STR114##                                          "    "       "                                                                                          ##STR115##                                          "    "       "                                                                                          ##STR116##                                          "    "       "                                                                                          ##STR117##                                          "    "       "                                                                                          ##STR118##                                          "    "       "                                                                                          ##STR119##                                          ______________________________________                                    

EXAMPLE 4

Instead of the mixture of the metal-containing indoaniline compoundsused in Example 2, a mixture of metal-containing indoaniline compounds(counter anion being (PF₆ -)₂) was prepared in the same manner as inExample 2 except that the metal salts represented by Example 2 compoundsA, B and M shown in Table 4 were used, and coated on a substrate toobtain a substrate having a thin coating layer with the maximumabsorption wavelength as shown in Table 4. To the thin coating layerthus obtained, writing was conducted by means of a semiconductor laseras a light source, whereby pits of uniform and clear shapes wereobtained. The C/N ratio was excellent, and the storage stability wasexcellent.

                                      TABLE 4                                     __________________________________________________________________________     ##STR120##                                                                                                                        Maximum absorp-                                                               tion wavelength          A                          B                         of the thin              No.                                                                              M R.sup.o                                                                          R.sup.p                                                                         K.sup.a          R.sup.q                                                                         R.sup.r                                                                          K.sup.b              coating layer            __________________________________________________________________________                                                         (nm)                     4-1                                                                              Ni                                                                              H  H                                                                                ##STR121##      H H                                                                                 ##STR122##          810                      4-2                                                                              " "  " "                " "                                                                                 ##STR123##          "                        4-3                                                                              " "  " "                " "                                                                                 ##STR124##          "                        4-4                                                                              " "  " "                " "                                                                                 ##STR125##          "                        4-5                                                                              " "  " "                " "                                                                                 ##STR126##          808                      4-6                                                                              Ni                                                                              H  H                                                                                ##STR127##      H H                                                                                 ##STR128##          808                      4-7                                                                              " "  " "                " "                                                                                 ##STR129##          "                        4-8                                                                              " "  " "                " "                                                                                 ##STR130##          806                      4-9                                                                              " "  " "                " "                                                                                 ##STR131##          805                      4-10                                                                             " "  " "                " "                                                                                 ##STR132##          807                      4-11                                                                             " "  " "                " "                                                                                 ##STR133##          812                      4-12                                                                             " "  "                                                                                ##STR134##      " "                                                                                 ##STR135##          805                      4-13                                                                             Ni                                                                              H  H                                                                                ##STR136##      H H                                                                                 ##STR137##          770   800                4-14                                                                             " "  " "                " "                                                                                 ##STR138##          808                      4-15                                                                             " "  " "                " "                                                                                 ##STR139##          800                      4-16                                                                             " "  " "                " "                                                                                 ##STR140##          809                      4-17                                                                             " "  " "                " "                                                                                 ##STR141##          "                        4-18                                                                             " "  " "                " "                                                                                 ##STR142##          808                      4-19                                                                             " "  " "                " "                                                                                 ##STR143##          "                        4-20                                                                             Ni                                                                              H  H                                                                                ##STR144##      H H                                                                                 ##STR145##          800                      4-21                                                                             " "  " "                " "                                                                                 ##STR146##          792                      4-22                                                                             " "  " "                " "                                                                                 ##STR147##          800                      4-23                                                                             " "  " "                " "                                                                                 ##STR148##          "                        4-24                                                                             " "  " "                " "                                                                                 ##STR149##          "                        4-25                                                                             Cu                                                                              "  " "                " "                                                                                 ##STR150##          "                        4-26                                                                             Co                                                                              "  " "                " "  "                    788                      4-27                                                                             Zn                                                                              H  H                                                                                ##STR151##      H H                                                                                 ##STR152##          810                      4-28                                                                             Ni                                                                              "  "                                                                                ##STR153##      " "                                                                                 ##STR154##          "                        4-29                                                                             " "  " "                " "                                                                                 ##STR155##          "                        4-30                                                                             " "  " "                " "                                                                                 ##STR156##          "                        __________________________________________________________________________       EXAMPLE 5

(a) Preparation 1.07 g of a compound of the formula: ##STR157## wasdissolved in 500 ml of ethanol. Then, a solution of 0.36 g of NiC₁₂.6 H₂O in 100 ml of water and a solution of 1.26 g of NH₄ PF₆ in 100 ml ofwater were mixed and dropwise added thereto over a period of about onehour. The mixture was stirred at room temperature for one hour. Then,100 ml of water was added thereto, and the mixture was stirred at roomtemperature for 2 hours. Formed precipitation were collected byfiltration under suction, washed with water and dried to obtain 0.70 gof a metal-containing indoaniline compound of the formula:

The visible range absorption spectrum (in chloroform) of this compoundwas λ_(max) 801 nm (ε_(max) 200000).

The analytical values obtained by the elemental analysis of thiscompound are as shown below, which are in good agreement with thecalculated values.

    ______________________________________                                        C (%)       H (%)     N (%)                                                   ______________________________________                                        Calculated                                                                            56.99   5.43      9.06  (C.sub.10 H.sub.75 N.sub.9 O.sub.3                                            P.sub.2 F.sub.12 Ni)                          values (%)                                                                    Analytical                                                                            56.83   5.51      8.76                                                values (%)                                                                    ______________________________________                                         (b) Recording medium

0.17 g of the metal-containing indoaniline compound obtained inPreparation (a) was dissolved in 10 g of 3-hydroxy-3-methyl-2-butanone,and the solution was filtered through a filter of 0.22 μm to obtain asolution. 3 ml of this solution was dropped on an injection moldedpolycarbonate resin substrate (5 inches) with grooves having a depth of650 Å and a width of 0.7 μm and coated by a spinner method at arotational speed of 700 rpm. After coating, the coating layer was driedat 60° C. for 10 minutes. The coating layer had a maximum absorptionwavelength of 800 nm and a reflectance of 40% (830 nm). The shape of thespectrum was broad. (c) Optical recording

While rotating the above recording medium at a speed of 4 m/sec, asemiconductor laser beam having a central wavelength of 830 nm wasirradiated with a pulse width of 500 nsec, whereby the C/N ratio was 56dB at an output of 6 mW. The sensitivity was flat without depending onthe thickness of the layer, and the initial characteristics wereexcellent with a secondary distortion of -40 dB. Yet, the storagestability (at 65° C. under a relative humidity of 80%) was excellent.Thus, it was excellent as an optical recording medium.

EXAMPLE 6

(a) Preparation

1.16 g of a compound of the formula: ##STR158## was dissolved in 500 mlof ethanol, and a solution of 0.44 g of NiCl₂.6H₂ O in 100 ml of waterwas added thereto. The mixture was stirred at room temperature for aboutone hour. Then, a solution of 1.26 g of NH₄ PF₆ in 100 ml of water wasdropwise added thereto, and the mixture was stirred at room temperaturefor one hour. Then, 100 ml of water was added thereto, and the mixturewas stirred for 2 hours. Formed precipitates were collected byfiltration under suction, washed with water and dried to obtain 1.20 gof a metal-containing indoaniline compound of the formula: ##STR159##

The visible range absorption spectrum (in chloroform) of this compoundwas λ_(max) 803 nm (ε_(max) 200000).

The analytical values obtained by the elemental analysis of thiscompound are shown below, which are in good agreement with thecalculated values.

    ______________________________________                                        C (%)       H (%)     N (%)                                                   ______________________________________                                        Calculated                                                                            58.62   5.94      8.54  (C.sub.72 H.sub.87 N.sub.9 O.sub.3                                            P.sub.2 F.sub.12 Ni)                          values (%)                                                                    Analytical                                                                            58.58   5.95      8.54                                                values (%)                                                                    ______________________________________                                    

(b) Recording medium

0.16 g of the metal-containing indoaniline compound obtained inPreparation (a) was dissolved in 10 g of 3-hydroxy-3-methyl-2-butanone,and the solution was filtered through a filter of 0.22 μm to obtain asolution. 5 ml of this solution was dropped on an injection moldedpolycarbonate resin substrate (5 inches) with grooves having a depth of700 Å and a width of 0.7 μm and coated by a spinner method at arotational speed of 800 rpm. After coating, the coated substrate wasdried at 60° C. for 10 minutes. The coated layer had a maximumabsorption wavelength of 805 nm and a reflectance of 38% (830 nm). Theshape of the spectrum was broad.

(c) Optical recording

While rotating the above recording medium at a speed of 4 m/sec, asemiconductor laser beam having a central wavelength of 830 nm wasirradiated with a pulse width of 500 nsec, whereby the C/N ratio was 55dB at an output of 6 mW. The sensitivity was flat without depending onthe thickness of the layer, and the initial characteristics wereexcellent with a secondary distortion of -41 dB. Yet, the storagestability (at 65° C. under a relative humidity of 80%) was excellent.Thus, it was excellent as an optical recording medium.

EXAMPLE 7

(a) Preparation

0.99 g of a compound of the formula: ##STR160## was dissolved in 500 mlof ethanol, and a solution of 0.44 g of CoCl₂.6H₂ O in 100 ml of waterwas added thereto. The mixture was stirred at room temperature for onehour. Then, a solution of 1.26 g of NH₄ PF₆ in 100 ml of water wasdropwise added thereto. Then, 100 ml of water was added, and formedprecipitates were collected by filtration under suction, washed withwater and dried to obtain 1.05 g of a metal-containing indoanilinecompound of the formula: ##STR161##

The visible range absorption spectrum (in chloroform) of this compoundwas λ_(max) 802 nm (ε_(max) 185000).

The analytical values obtained by the elemental analysis of thiscompound are shown below, which are in good agreement with thecalculated values.

    ______________________________________                                        C (%)       H (%)     N (%)                                                   ______________________________________                                        Calculated                                                                            55.14   4.85      9.64  (C.sub.60 H.sub.63 N.sub.9 O.sub.3                                            P.sub.2 F.sub.12 Ni)                          values (%)                                                                    Analytical                                                                            55.43   4.90      9.58                                                values (%)                                                                    ______________________________________                                    

(b) Recording medium

0.15 g of the mixture of the metal-containing indoaniline compoundsobtained in Preparation (a) was dissolved in 10 g of diacetone alcoholfiltered through a filter of 0.22 μm to obtain a solution. 5 ml of thissolution was then dropped on an injection molded polycarbonate resinsubstrate (5 inches) with grooves having a depth of 700 Å and a width of0.7 μm and coated by a spinner method at a rotational speed of 700 rpm.After coating, the coating layer was dried at 60° C. for 10 minutes. Thecoating layer had a maximum absorption wavelength of 806 nm and areflectance of 36% (830 nm). The shape of the spectrum was broad.

(c) Optical recording

While rotating the above recording medium at a speed of 4 m/sec, asemiconductor laser beam having a central wavelength of 830 nm wasirradiated with a pulse width of 500 nsec, whereby the C/N ratio was 54dB at an output of 6 mW. The sensitivity was flat without depending onthe thickness of the layer, and the initial characteristics wereexcellent with a secondary distortion of -42 dB. Yet, the storagestability (at 65° C. under a relative humidity of 80%) was excellent.Thus, it was excellent as an optical recording medium.

EXAMPLE 8

(a) Preparation

1.07 g of a compound of the formula: ##STR162## was dissolved in 500 mlof ethanol, and a solution of 6.6 g of NiCl₂.6H₂ O in 100 ml of waterwas added thereto. The mixture was stirred at room temperature for onehour. Then, a solution of 1.26 g of NH₄ PF₆ in 100 ml of water wasdropwise added thereto, and the mixture was stirred at room temperaturefor about 2 hours. Then, 100 ml of water was added thereto, wherebyprecipitates were formed. The stirring was continued in the suspendedstate for about one hour. Formed precipitates were collected byfiltration under suction, washed with water and dried to obtain 0.82 gof a mixture of the metal-containing indoaniline compounds of theformula: ##STR163##

The visual region absorption spectrum in chloroform of this product wasλ_(max) 800 nm (ε_(max) 180000).

(b) Recording medium

0.15 g of the metal-containing indoaniline compound obtained inPreparation (a) was dissolved in 10 g of diacetone alcohol, and thesolution was filtered through a filter of 0.22 μm to obtain a solution.5 ml of this solution was dropped on an injection molded polycarbonateresin substrate (5 inches) with grooves having a depth of 700 Å and awidth of 0.7 μm and coated by a spinner method at a rotational speed of700 rpm. After coating, the coating layer was dried at 6020 C. for 10minutes. The coating layer had a maximum absorption wavelength of 803 nmand a reflectance of 40% (830 nm). The shape of the spectrum was broad.

(c) Optical recording

While rotating the above recording medium at a speed of 4 m/sec, asemiconductor laser beam having a central wavelength of 830 nm wasirradiated with a pulse width of 500 nsec, whereby the C/N ratio was 53dB at an output of 6 mW. The storage stability (at 65° C. under arelative humidity of 80%) was excellent. Thus, it was excellent as anoptical recording medium.

EXAMPLE 9

Instead of the dye used in Example 5, each of the compounds identifiedin Table 5 was prepared and coated on a substrate in the same manner asin Example 5 to obtain a substrate having a thin coating layer with themaximum asorption wavelength as identified in Table 5. To the thincoating layer thus obtained, writing was conducted by means of asemiconductor laser as a light source, whereby pits of uniform and clearshapes were obtained. The sensitivity and the C/N ratio were excellent.The initial characteristics (the dependency of sensitivity on thethickness of the recording layer, and the secondary distortion) wereexcellent. Yet, the storage stability was excellent. Thus, it wasexcellent as an optical recording medium.

In addition to the compounds used in the preceding Examples, specificexamples of the metal-containing indoaniline compounds useful for theoptical recording medium of the present invention include compoundsidentified in Table 6 and compounds of the formula IV wherein each ofX¹, X² and X³ is 2-CH₃, each of Y¹, Y² and Y³ is a hydrogen atom, eachof R⁷, R⁸, R⁹, R¹⁰, R¹¹ and R¹² is a hydrogen atom, and R¹, R², R³, R⁴,R⁵, R⁶, M and p are as identified in Table 7.

                                      TABLE 5                                     __________________________________________________________________________     ##STR164##                                                                                                        Maximum absorp-                                                               tion wavelength                                                               of the thin                              Na M R.sup.x                                                                             R.sup.y                                                                           K                     coating layer (nm)                       __________________________________________________________________________    9-1                                                                              Ni                                                                              H     H                                                                                  ##STR165##           808                                      9-2                                                                              " "     "                                                                                  ##STR166##           809                                      9-3                                                                              Ni                                                                              H     H                                                                                  ##STR167##           808                                      9-4                                                                              " "     "                                                                                  ##STR168##           811                                      9-5                                                                              " "     "                                                                                  ##STR169##           812                                      9-6                                                                              " "     "                                                                                  ##STR170##           814                                      9-7                                                                              Ni                                                                              2-CH.sub.3                                                                          H                                                                                  ##STR171##           815                                      9-8                                                                              " "     "                                                                                  ##STR172##           783                                      9-9                                                                              " 6- or 7-Cl                                                                          "                                                                                  ##STR173##           835                                      9-10                                                                             " C.sub.2 H.sub.5                                                                     "                                                                                  ##STR174##           808                                      9-11                                                                             Ni                                                                              H     H                                                                                  ##STR175##           808                                      9-12                                                                             " "     "                                                                                  ##STR176##           809                                      9-13                                                                             " 6-CH.sub.3                                                                          "                                                                                  ##STR177##           812                                      9-14                                                                             " H     "                                                                                  ##STR178##           820                                      9-15                                                                             Ni                                                                              H     H                                                                                  ##STR179##           813                                      9-16                                                                             Cu                                                                              "     "                                                                                  ##STR180##           810                                      9-17                                                                             Co                                                                              "     "                                                                                  ##STR181##           809                                      9-18                                                                             Ni                                                                              6- or 7-Cl                                                                          2-CH.sub.3                                                                         ##STR182##           841                                      9-19                                                                             Cu                                                                              H     H                                                                                  ##STR183##           805                                      9-20                                                                             " "     "                                                                                  ##STR184##           785                                      9-21                                                                             Zn                                                                              "     "                                                                                  ##STR185##           804                                      9-22                                                                             " "     "                                                                                  ##STR186##           803                                      9-23                                                                             Co                                                                              H     H                                                                                  ##STR187##           789                                      9-24                                                                             " "     "                                                                                  ##STR188##           791                                      9-25                                                                             Cu                                                                              6- or 6-Cl                                                                          2-CH.sub.3                                                                         ##STR189##           837                                      9-26                                                                             Co                                                                              H     "                                                                                  ##STR190##           798                                      9-27                                                                             Ni                                                                              H     H                                                                                  ##STR191##           792                                      9-28                                                                             " "     "                                                                                  ##STR192##           792                                      9-29                                                                             " "     "                                                                                  ##STR193##           796                                      9-30                                                                             " "     "                                                                                  ##STR194##           777                                      9-31                                                                             Ni                                                                              H     H                                                                                  ##STR195##           762                                      9-32                                                                             " "     "                                                                                  ##STR196##           796                                      9-33                                                                             " "     "                                                                                  ##STR197##           796                                      9-34                                                                             " "     "                                                                                  ##STR198##           807                                      9-35                                                                             Ni                                                                              H     H                                                                                  ##STR199##           805                                      9-36                                                                             " "     "                                                                                  ##STR200##           799                                      9-37                                                                             " "     "                                                                                  ##STR201##           791                                      9-38                                                                             " "     "                                                                                  ##STR202##           796                                      9-39                                                                             Ni                                                                              H     "                                                                                  ##STR203##           789                                      9-40                                                                             " "     "                                                                                  ##STR204##           778                                      9-41                                                                             " "     "                                                                                  ##STR205##           788                                      9-42                                                                             " "     "                                                                                  ##STR206##           774                                      9-43                                                                             Ni                                                                              H     H                                                                                  ##STR207##           788                                      9-44                                                                             " "     "                                                                                  ##STR208##           776                                      9-45                                                                             " "     "                                                                                  ##STR209##           786                                      9-46                                                                             " "     "                                                                                  ##STR210##           789                                      9-51                                                                             Ni                                                                              H     H                                                                                  ##STR211##           803                                      9-52                                                                             " "     "                                                                                  ##STR212##           800                                      9-53                                                                             " "     "                                                                                  ##STR213##           800                                      9-54                                                                             " "     "                                                                                  ##STR214##           816                                      9-55                                                                             Ni                                                                              H     H                                                                                  ##STR215##           807                                      9-56                                                                             " "     "                                                                                  ##STR216##           733                                      9-57                                                                             " "     "                                                                                  ##STR217##           830                                      9-58                                                                             " "     "                                                                                  ##STR218##           809                                      9-59                                                                             Ni                                                                              H     H                                                                                  ##STR219##           818                                      9-60                                                                             " "     "                                                                                  ##STR220##           818                                      9-61                                                                             " "     "                                                                                  ##STR221##           802                                      9-62                                                                             " "     "                                                                                  ##STR222##           801                                      9-63                                                                             Ni                                                                              H     H                                                                                  ##STR223##           790                                      9-64                                                                             " "     "                                                                                  ##STR224##           790                                      9-65                                                                             " 4-CH.sub.3                                                                          6-CH.sub.3                                                                         ##STR225##           813                                      9-66                                                                             " "     "                                                                                  ##STR226##           810                                      __________________________________________________________________________

                  TABLE 6                                                         ______________________________________                                         ##STR227##                                                                   M     R.sup.x                                                                              R.sup.y   K                                                      ______________________________________                                        Ni    H      H                                                                                        ##STR228##                                            "     "      "                                                                                        ##STR229##                                            "     "      "                                                                                        ##STR230##                                            "     "      7-OCH.sub.3                                                                              ##STR231##                                            Ti    H      H                                                                                        ##STR232##                                            Fe    "      "                                                                                        ##STR233##                                            VO    "      "                                                                                        ##STR234##                                            Cr    "      "                                                                                        ##STR235##                                            Pt    "      "                                                                                        ##STR236##                                            Ni    "      "                                                                                        ##STR237##                                            Ni    H      H                                                                                        ##STR238##                                            "     "      7-CN                                                                                     ##STR239##                                            "     "      7-NO.sub.2                                                                               ##STR240##                                            Mn    "      H                                                                                        ##STR241##                                            Ni    "      "                                                                                        ##STR242##                                            "     "      "                                                                                        ##STR243##                                            Ni    H      H                                                                                        ##STR244##                                            "     "      "                                                                                        ##STR245##                                            "     "      "                                                                                        ##STR246##                                            "     "      "                                                                                        ##STR247##                                            "     "      "                                                                                        ##STR248##                                            "     "      "                                                                                        ##STR249##                                            ______________________________________                                    

                                      TABLE 7                                     __________________________________________________________________________    M R.sup.1                                                                          R.sup.2                                                                          R.sup.3                                                                            R.sup.4                                                                              R.sup.5 R.sup.6    p                                      __________________________________________________________________________    Ni                                                                              C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  C.sub.3 H.sub.7 (n)                                                                C.sub.3 H.sub.7 (n)                                                                  C.sub.4 H.sub.9 (n)                                                                   C.sub.3 H.sub.7 (n)                                                                      2                                      " "  "  "    "      C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                         "                                      " "  "  "    "      C.sub.4 H.sub.9 (n)                                                                   C.sub.2 H.sub.5                                                                          "                                      Zn                                                                              "  "  "    "      C.sub.5 H.sub.11 (n)                                                                  C.sub.5 H.sub.11 (n)                                                                     "                                      Co                                                                              "  "  "    "      CH.sub.2 CHCH.sub.2                                                                   CH.sub.2 CHCH.sub.2                                                                      "                                      " "  "  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.5                                                                      C.sub.4 H.sub.9 (n)                                                                   C.sub.2 H.sub.4 OCH.sub.2 CHCH.sub.2                                                     3                                      Co                                                                              C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                    C.sub.2 H.sub.4 OC.sub.2 H.sub. 5                                                    C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                      C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                         3                                      Al                                                                              "  "  "    "      C.sub.4 H.sub.9 (n)                                                                   "          "                                      Fe                                                                              "  "  "    "      "       C.sub.2 H.sub.4 OCH.sub.3                                                                3                                      " "  "  "    C.sub.2 H.sub.5                                                                      C.sub.6 H.sub.13 (n)                                                                  C.sub.6 H.sub.13 (n)                                                                     "                                      Al                                                                              "  "  "    "      C.sub.4 H.sub.9 (n)                                                                   C.sub.2 H.sub.4 OH                                                                       "                                      Ni                                                                              "  "  "    "      C.sub.2 H.sub.5                                                                        ##STR250##                                                                              2                                      __________________________________________________________________________

We claim:
 1. A metal-containing indoaniline compound having the formula:##STR251## wherein M is a metal atom of Group VIII, Ib, IIb, IIIb, IVa,Va, VIa or VIIa of the Periodic Table or its halide or oxide, rings A,B, C, D, E and F may have substituents, each of K¹, K² and K³ is aresidue of a substituted or unsubstituted aromatic amine, each of 1, mand n is 0 or 1, provided 1+m+n=2 or 3, and p is 2, 3 or
 4. 2. Themetal-containing indoaniline compound according to claim 1, which hasthe formula: ##STR252## wherein M is a metal atom of Group VIII, Ib,IIb, IIIb, IVa, Va, VIa or VIIa of the Periodic Table, each of R⁷, R⁸,R⁹, R¹⁰, R¹¹, R¹², X¹, X², X³, Y¹, Y² and Y³ is a hydrogen atom, ahalogen atom, an alkyl group, an alkoxy group, an acylamino group, analkoxycarbonylamino group or an alkylsulfonylamino group, each of R¹,R², R³, R⁴, R⁵ and R⁶ is a hydrogen atom, a C₁₋₂₀ alkyl group, an arylgroup, an alkenyl group or a cycloalkyl group, which may be substituted,each of 1, m and n is 0 or 1, provided 1+m+n=2 or 3, and p is 2, 3 or 4.3. The metal-containing indoaniline compound according to claim 1, whichhas the formula: ##STR253## wherein M is a metal atom of Ni, Cu, Co, Znor Fe, each of X⁴, X⁵ and X⁶ is a hydrogen atom or a C₁₋₄ alkyl group,each of R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ is a C₁₋₈ alkyl group, analkoxyalkyl group, an alkoxyalkoxyalkyl group, analkoxyalkoxyalkoxyalkyl group, an allyloxyalkyl group, an arylalkylgroup, an aryloxyalkyl group, a cyanoalkyl group, a hydroxyalkyl group,a tetrahydrofurylalkyl group, an alkylsulfonylaminoalkyl group, anacyloxyalkyl group or an alkenyl group, each of R¹⁹, R²⁰ and R²¹ is ahydrogen atom, a C₁₋₄ alkyl group or a halogen atom, and each of 1, mand n is 0 or 1, provided 1+m+n=2 or
 3. 4. The metal-containingindoaniline compound according to claim 3, wherein in the formula III,each of X⁴, X⁵ and X⁶ is a C₁₋₄ alkyl group, each of R¹³, R¹⁴, R¹⁵, R¹⁶,R¹⁷ and R¹⁸ is a C₁₋₆ alkyl group, and each of R¹⁹, R²⁰ and R²¹ is ahydrogen atom or a C₁₋₄ alkyl group.
 5. An optical recording mediumcomprising a substrate and a recording layer containing a dye formed onthe substrate wherein the recording is effected by irradiation of alaser beam to impart a thermal deformation to the recording layer andthe reproduction is done by reading a difference in the reflectancebetween the deformed portion and the undeformed portion of the recordinglayer, said dye being a metal-containing indoaniline compound having theformula: ##STR254## wherein M is a metal atom of Group VIII, Ib, IIb,IIIb, IVa, Va, VIa or VIIa of the Periodic Table or its halide or oxide,rings A, B, C, D, E and F may have substituents, each of K¹, K² and K³is a residue of a substituted or unsubstituted aromatic amine, each of1, m and n is 0 or 1, provided 1+m+n=2 or 3, and p is 2, 3 or
 4. 6. Theoptical recording medium according to claim 5, wherein themetal-containing indoaniline compound has the formula: ##STR255##wherein M is a metal atom of Group VIII, Ib, IIb, IIIb, IVa, Va, VIa orVIIa of the Periodic Table, each of R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², X¹, X²,X³, Y¹, Y² and Y³ is a hydrogen atom, a halogen atom, an alkyl group, analkoxy group, an acylamino group, an alkoxycarbonylamino group or analkylsulfonylamino group, each of R¹, R², R³, R⁴, R⁵ and R⁶ is ahydrogen atom, a C₁₋₂₀ alkyl group, an aryl group, an alkenyl group or acycloalkyl group, which may be substituted, each of 1, m and n is 0 or1, provided 1+m+n=2 or 3, and p is 2, 3 or
 4. 7. The optical recordingmedium according to claim 5, wherein the metal-containing indoanilinecompound has the formula: ##STR256## wherein M is a metal atom of Ni,Cu, Co, Zn or Fe, each of X⁴, X⁵ and X⁶ is a hydrogen atom or a C₁₋₄alkyl group, each of R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ is a C₁₋₈ alkylgroup, an alkoxyalkyl group, an alkoxyalkoxyalkyl group, analkoxyalkoxyalkoxyalkyl group, an allyloxyalkyl group, an arylalkylgroup, an aryloxyalkyl group, a cyanoalkyl group, a hydroxyalkyl group,a tetrahydrofurylalkyl group, an alkylsulfonylaminoalkyl group, anacyloxyalkyl group or an alkenyl group, each of R¹⁹, R²⁰ and R²¹ is ahydrogen atom, a C₁₋₄ alkyl group or a halogen atom, and each of 1, mand n is 0 or 1, provided 1+m+n=2 or
 3. 8. The optical recording mediumaccording to claim 7, wherein in the formula III, each X⁴, X⁵ and X⁶ isa C₁₋₄ alkyl group, each of R¹³, R¹⁴, R¹⁵, R¹⁶, R¹⁷ and R¹⁸ is a C₁₋₆alkykl group, and each of R¹⁹, R²⁰ and R²¹ is a hydrogen atom or a C₁₋₄alkyl group.